Electrode assembly

ABSTRACT

The present invention is directed to an electrochemical apparatus comprising of an electrode assembly, an internal reservoir and an internal dryer. The internal dryer consists of a chamber filled with a multitude of balls to create mechanical obstacles removing moisture from gasses present inside, reducing the volume of accumulated gasses and acting as anti-splash for the electrolyte. The invention is also directed to an electrode assembly of monopolar electrodes for use in electrical apparatus. The bipolar electrode assembly comprises a pair of electrodes ( 12, 14 ), each of the electrodes having a plurality of electrode plates ( 16, 18 ) connected in series together. The electrode plates of each of the electrodes are connected to the next electrode plate in the series by a bridging member ( 20 ) contiguous with each of the interconnected electrode plates. The invention is also directed to an electrode for use in an electrode assembly. The electrode comprises a plurality of parallel spaced apart electrode plates connected in series to each other. Each of the electrode plates is connected to the next plate in the series by a bridging strap contiguous with each of the interconnected electrode plates.

FIELD OF THE INVENTION

The present invention is directed to an electrode assembly for use inelectrical apparatus, in particular where the electrode assembly is amonopolar multi-plate electrode assembly with the individual electrodeplates of the same polarity connected together by a bridging strapcontiguous with each of the interconnected electrode plates.

BACKGROUND OF THE INVENTION

Various configurations of electrode assemblies are used in a number ofdifferent electrical apparatuses. Such electrical apparatus includemulti-plate storage batteries, electrolysis and other electrochemicalcells. Electrode assemblies may be either monopolar or bipolar dependingupon the nature of the electrical apparatus and the required propertiesof the electrode assembly. Bipolar electrode assemblies have a pluralityof individual plates with the opposite sides of each of the platescarrying the positive and negative charges. Another type of electrodeassembly is a monopolar electrode assembly which has positive andnegative electrode plates interleaved with one another. Monopolarelectrode assemblies are commonly utilized in storage batteries andelectrolysis and other electrochemical cells. Depending upon theapplication, the electrode plates may be separated by electrolyte, orthe electrode assembly may be provided with electrically inertseparators, such as glass mat separators, commonly utilized in lead acidstorage batteries.

Monopolar electrode assemblies are provided with connectors on theoutside plates of the assemblies for connecting the electrical apparatusinto electrical circuits. Bipolar electrode assemblies require that inaddition to the connectors on the outside plates of the assembly, theindividual anodes or cathodes are charging the surfaces through theelectrolyte. For monopolar assemblies, most commonly, the anodes orcathodes are interconnected together by providing a lug at an uppercorner of the electrode plate, the lugs being interconnected by a busbaror by fusing or welding the lugs together. This interconnection orfusing of the lugs results in connector junctions, which requireadditional steps in the manufacturing process. In addition, connectorjunctions may cause local increases in current density in the connectorjunction, potentially reducing the efficiency of the electrode assembly.

SUMMARY OF THE INVENTION

In one aspect, the present invention is directed to an assembly ofmonopolar electrodes for use in electrical apparatus. The electrodeassembly comprises a pair of electrodes, each of the electrodes having aplurality of spaced apart electrode plates connected together inline.The electrode plates of each of the electrodes are connected to the nextelectrode plate in the series by a bridging member contiguous with eachof the interconnected electrode plates.

In another aspect of the invention, there is provided an electrode foruse in an electrode assembly. The electrode comprises a plurality ofparallel spaced apart electrode plates connected in series. Each of theelectrode plates is connected to the next plate in the series by abridging strap contiguous with each of the interconnected electrodeplates.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are shown in the drawings,wherein:

FIG. 1 is a perspective view of an electrode assembly according to thepresent invention;

FIG. 2 is a plan view of an electrode for use in the electrode assemblyof FIG. 1; and

FIG. 3 is a perspective view, partly in cross-section of an electrolysiscell utilizing the electrode assembly of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of an electrode assembly according to the presentinvention is illustrated in the figures, generally indicated by thenumeral 10. Electrode assembly 10 illustrated in the figures is anassembly of two monopolar multi-plate electrodes made up of an anode 12and a cathode 14. The electrode assembly 10 illustrated in the figuresis of particular use in an electrolysis cell for generation of hydrogengas, although, as explained below, the electrode assembly 10 can be usedin other types of electrical apparatuses.

Each of the individual electrodes, anode 12 and cathode 14 are made upof spaced apart inter-connected electrode plates 16 and 18. Theelectrode plates 16 and 18 of the anode 12 and cathode 14 areinterconnected to one another by bridging members 20 and 22 respectivelycontiguous with and connecting together the individual electrode plates16. Thus anode plates 16 are interconnected by bridging members 20 at alower edge of the anode plates 16. Similarly, the individual cathodeplates 18 are interconnected by bridging members 22 located at an upperedge thereof.

FIG. 2 illustrates a plan view of an individual electrode for use in theelectrode assembly 10. The electrode illustrated is an anode 12,however, the cathode 14 is similarly constructed. The individualelectrode is formed from a metal blank of a suitable metal material byremoving sections of the metal blank to provide for the series ofelectrode plates 16 interconnected together by the bridging members 20.For use in an electrolysis cell for generation of hydrogen gas, themetal used for construction of the electrodes is preferably a suitablestainless steel, most preferably nickel plated stainless steel. Theselection of the suitable metal for use in other applications or otherelectrical apparatuses would be readily apparent to those skilled in theart.

Once the electrode 12 is formed, it is bent into an accordian shape toprovide the parallel spaced apart electrode plates 16 for the individualelectrode. As set out in the figures, one of the electrodes has thebridging members 20 located along the edge adjacent the top, while theother electrode has the bridging members 22 located along the edgeadjacent the bottom. The two individual electrodes are then interleavedby sliding one electrode into the other with the plates of the firstelectrode passing between the plates of the second electrode. Once thetwo electrode plates are interleaved, they may be held in the properposition and spacing by use of a cartridge to hold the electrodes. Thecartridge may be provided by using spacer blocks to hold the upperand/or lower ends of the electrode plates in position the spacer blocksbeing joined to one another by a suitable means such as bolts and nuts.The spacer blocks, bolts and nuts are constructed of a suitablenon-conducting material, which is resistant to the physical and chemicalenvironment of the electrical apparatus in which the electrode assemblyis to be used. Preferrably, for an electrolysis cell, the spacer blocks,bolts and nuts are polypropylene.

The details of an electrochemical cell 50 utilizing an electrodeassembly of the present invention are shown in FIG. 3. Theelectrochemical cell 50 is an electrolysis cell utilized in a hydrogengenerating system to generate small quantities of hydrogen and oxygenwith the hydrogen and oxygen generated then being combined with theusual air/fuel mixture to improve the efficiency of internal combustionengines. A typical such hydrogen generating system includes theelectrolysis cell 50 for generating hydrogen and oxygen gases byelectrolysis of an aqueous solution, a power source for providingelectrical power to the electrolysis cell, an outlet flow means forintroducing the generated gases into the intake manifold system of aninternal combustion engine, a monitoring means for monitoring theoperating conditions of the hydrogen generating system, and a controlmeans connected to the monitoring means for controlling the operation ofthe hydrogen generating system in response to the monitoring means. Onesuch hydrogen generating system as described in co-pending Canadianpatent application number 2,209,237 includes an electrolysis cell 10which is used to generate the hydrogen and oxygen gases by electrolysisof a suitable aqueous medium. In the system described, the gasesgenerated by the electrolysis cell are fed through a moisture trap whichis connected to the cell by a suitable tubing which is provided with acheck valve to prevent the back flow of fluids into the electrolysiscell. The output of the moisture trap is connected to a bubbler by meansof a suitable tubing which is also provided with a check valve toprevent back flow of fluids. From the bubbler the gases flow throughtubing to a filter to remove any particulate material or residualmoisture in the gases. From the filter the gases flow through tubing toa flow control valve which is adjustable to regulate the flow of thegases. The output of the flow control valve is connected to a pump whichpumps the gases to a suitable part of the intake system of the engine.

Electrochemical cell 50, preferably has a cylindrical shaped case 52,constructed of a suitable material which would be inert to theelectrolyte solution and would not be affected by the voltages ortemperatures encountered in the electrolysis cell 50. The case 52 shouldalso preferably have a co-efficient of expansion, which does not causesignificant expansion of the dimensions of the cell 50 under theoperating conditions of the hydrogen generating system. Preferably, thecase 52 of the electrolysis cell 50 is a polyvinyl chloride. While thecase 52 may be provided as a one-piece mold, it is preferred that foruniformity, the case 52 be in two sections, the sidewall 54 and the base56 which are PVC welded to give the characteristics of a one-piecestructure.

The electrochemical cell 50 is provided with a welded on cap 58, whichrepresents a gas accumulation zone. The cap 58 is provided with a firstopening 60 for an outlet of the electrolysis cell 50 to which tubing forthe generated gas is connected. Cap 58 is provided with a second opening62 for receiving a fill plug 64. Fill plug 64 is utilized to allow theaddition of distilled water or electrolyte solution to the cell 50 asthe level of fluid in the electrolysis cell 50 decreases. Fill plug 64may also incorporate a pressure release mechanism to provide for reliefof the pressure within the cell 50 should the interior pressure increasebeyond a set limit. The fill plug 64 may also function as a ruptureplug. In case of malfunction, when internal pressure builds up the plugwill be pushed away from its seat, providing an opening for the gassesto be relieved to the atmosphere.

An optical level indicator 81 is assembled to top cap 58 to allowobservation when maximum liquid level is reached. This is extremelyuseful for the fill-up procedure. Optionally the reservoir 80 can beprovided with a level sensing means to provide information on actuallevel of electrolyte, or signalize that a predetermined minimum levelhas been reached.

The electrolysis cell 50 is provided with an electrode assembly 10mounted in a cartridge according to the present invention. The cathodeand anode electrode plates 16 and 18 are provided with adapters 70 forelectrical connection to the positive and negative supply from the motorvehicle electrical system. When the electrode assembly is placed withinthe case 52, the adapters 70 are aligned with openings 72 in the case 52for connection of a terminal 74. The portion of the interior of the case52 where the electrode assembly is located, provides the reservoirchamber for holding of the electrolyte solution and operation of theelectrolysis. The above of the reservoir chamber is provided aperforated spacer disc to separate the gas accumulation zone from thereservoir chamber.

The gas accumulation chamber 70 is filled with a multitude of balls 71made of an inert material, preferably polypropylene. The balls 71 playthe role of a mechanical barrier for the gasses exiting the cell 50,removing airborne moisture particles and drying the gasses. Also theyact as an anti-splash for the electrolyte and reduce the volume ofaccumulated gasses limiting the negative repercussions in case of asecondary ignition inside the cell 50.

The electrolyte solution utilized within the electrolysis cell 10, ispreferably a basic aqueous solution to provide for increased efficiencyof the electrolysis reaction. Preferably, the solution is also adjustedto remain in solution form and not freeze at extremely low temperatures,down to −40° C. or more. Most preferably, the electrolyte solution is a20 to 30% KOH solution.

Although various preferred embodiments of the present invention havebeen described herein in detail, it will be appreciated by those skilledin the art, that variations may be made thereto without departing fromthe spirit of the invention or the scope of the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. An assembly of monopolarelectrodes for use in an electrical apparatus, the electrode assemblycomprising a first multi-plate electrode interleaved with a secondmulti-plate electrode, wherein: each multi-plate electrode includes adiscrete series of parallel plates connected together in series bybridging members such that each plate other than the first and last inthe series of plates is connected to the plate before it and the plateafter it in the series by two discrete bridges, one at each of twoopposed edges of the plate; the plates of the first multi-plateelectrode alternate with the plates of the second multi-plate electrodeand do not contact the plates of the second multi-plate electrode; andthe bridging members of the first multi-plate electrode do not contactthe bridging members of the second multi-plate electrode.
 2. Theelectrode assembly as defined in claim 1, wherein: each multi-plateelectrode is formed from a discrete blank by removal of sections thatleave a discrete bridging member between each pair of successive platesin a series of plates and then bending the plates into an accordionshape at the bridging members so that the plates are parallel.
 3. Theelectrode assembly as defined in claim 2, wherein the electrode assemblymay be assembled by sliding the first multi-plate electrode into asecond multi-plate electrode so that the plates of the first multi-plateelectrode alternate with the plates of the second multi-plate electrode.4. The electrode assembly as defined in claim 3, wherein: each plate ofeach multi-plate electrode has a discrete top edge, a discrete bottomedge, and two discrete side edges; each bridging member of the firstmulti-plate electrode connects a side edge of one plate of a discretepair of successive plates of the first multi-plate electrode with a sideedge of the other plate of that pair of plates adjacent the top edges ofthose plates; and each bridging member of the second multi-plateelectrode connects a side edge of one plate of a discrete pair ofsuccessive plates of the second multi-plate electrode with a side edgeof the other plate of that pair of plates adjacent the bottom edges ofthose plates.
 5. The electrode assembly as defined in claim 2, wherein:each plate of each multi-plate electrode has a discrete top edge, adiscrete bottom edge, and two discrete side edges; each bridging memberof the first multi-plate electrode connects a side edge of one plate ofa discrete pair of successive plates of the first multi-plate electrodewith a side edge of the other plate of that pair of plates adjacent thetop edges of those plates; and each bridging member of the secondmulti-plate electrode connects a side edge of one plate of a discretepair of successive plates of the second multi-plate electrode with aside edge of the other plate of that pair of plates adjacent the bottomedges of those plates.
 6. The electrode assembly as defined in claim 1,wherein the electrode assembly is assembled by sliding the firstmulti-plate electrode into a second multi-plate electrode so that theplates of the first multi-plate electrode alternate with the plates ofthe second multi-plate electrode.
 7. The electrode assembly as definedin claim 6 wherein: each plate of each multi-plate electrode has adiscrete top edge, a discrete bottom edge, and two discrete side edges;each bridging member of the first multi-plate electrode connects a sideedge of one plate of a discrete pair of successive plates of the firstmulti-plate electrode with a side edge of the other plate of that pairof plates adjacent the top edges of those plates; and each bridgingmember of the second multi-plate electrode connects a side edge of oneplate of a discrete pair of successive plates of the second multi-plateelectrode with a side edge of the other plate of that pair of platesadjacent the bottom edges of those plates.
 8. The electrode assembly asdefined in claim 1, wherein: each plate of each multi-plate electrodehas a discrete top edge, a discrete bottom edge, and two discrete sideedges; each bridging member of the first multi-plate electrode connectsa side edge of one plate of a discrete pair of successive plates of thefirst multi-plate electrode with a side edge of the other plate of thatpair of plates adjacent the top edges of those plates; and each bridgingmember of the second multi-plate electrode connects a side edge of oneplate of a discrete pair of successive plates of the second multi-plateelectrode with a side edge of the other plate of that pair of platesadjacent the bottom edges of those plates.
 9. A multi-plate electrodefor use as a monopolar electrode in an electrode assembly in anelectrical apparatus, the multi-plate electrode comprising a series ofparallel plates connected together in series by bridging members suchthat each plate other than the first and last in the series of plates isconnected to the plate before it and the plate after it in the series bytwo discrete bridges, one at each of two opposed edges of the plate. 10.The multi-plate electrode as defined in claim 9, wherein the multi-plateelectrode is formed from a blank by removal of sections that leave adiscrete bridging member between each pair of successive plates in aseries of plates and then bending the plates into an accordion shape atthe bridging members so that the plates are parallel.
 11. Anelectrochemical cell for production of gases by electrolysis the cellcomprising an electrode assembly located in a liquid reservoir and aninternal gas dryer including a gas accumulation chamber above the liquidreservoir, the gas accumulation chamber filled with a multitude of ballsof inert material, the balls providing a mechanical barrier for removingairborne moisture, reducing the volume of accumulated gasses andreducing splashing of liquid.
 12. An electrochemical cell as claimed inclaim 11, additionally comprising a means for sensing and monitoringliquid levels.
 13. An electrochemical cell as defined in claim 12,wherein the electrode assembly comprises: first multi-plate electrodeinterleaved with a second multi-plate electrode, wherein: eachmulti-plate electrode includes a discrete series of parallel platesconnected together in series by bridging members such that each plateother than the first and last in the series of plates is connected tothe plate before it and the plate after it in the series by two discretebridges, one at each of two opposed edges of the plate; the plates ofthe first multi-plate electrode alternate with the plates of the secondmulti-plate electrode and do not contact the plates of the secondmulti-plate electrode; and the bridging members of the first multi-plateelectrode do not contact the bridging members of the second multi-plateelectrode.
 14. The electrochemical cell as defined in claim 13, wherein:each multi-plate electrode is formed from a discrete blank by removal ofsections that leave a discrete bridging member between each pair ofsuccessive plates in a series of plates and then bending the plates intoan accordion shape at the bridging members so that the plates areparallel.
 15. The electrode assembly as defined in claim 14, whereineach plate of each multi-plate electrode has a discrete top edge, adiscrete bottom edge, and two discrete side edges; each bridging memberof the first multi-plate electrode connects a side edge of one plate ofa discrete pair of successive plates of the first multi-plate electrodewith a side edge of the other plate of that pair of plates adjacent thetop edges of those plates; and each bridging member of the secondmulti-plate electrode connects a side edge of one plate of a discretepair of successive plates of the second multi-plate electrode with aside edge of the other plate of that pair of plates adjacent the bottomedges of those plates, wherein the electrode assembly may be assembledby sliding the first multi-plate electrode into a second multi-plateelectrode so that the plates of the first multi-plate electrodealternate with the plates of the second multi-plate electrode.
 16. Anelectrochemical cell as defined in claim 11, wherein the electrodeassembly comprises: first multi-plate electrode interleaved with asecond multi-plate electrode, wherein: each multi-plate electrodeincludes a discrete series of parallel plates connected together inseries by bridging members such that each plate other than the first andlast in the series of plates is connected to the plate before it and theplate after it in the series by two discrete bridges, one at each of twoopposed edges of the plate; the plates of the first multi-plateelectrode alternate with the plates of the second multi-plate electrodeand do not contact the plates of the second multi-plate electrode; andthe bridging members of the first multi-plate electrode do not contactthe bridging members of the second multi-plate electrode.
 17. Theelectrochemical cell as defined in claim 16, wherein: each multi-plateelectrode is formed from a discrete blank by removal of sections thatleave a discrete bridging member between each pair of successive platesin a series of plates and then bending the plates into an accordionshape at the bridging members so that the plates are parallel.
 18. Theelectrochemical cell as defined in claim 17, wherein the electrodeassembly may be assembled by sliding the first multi-plate electrodeinto a second multi-plate electrode so that the plates of the firstmulti-plate electrode alternate with the plates of the secondmulti-plate electrode.
 19. The electrode assembly as defined in claim18, wherein each plate of each multi-plate electrode has a discrete topedge, a discrete bottom edge, and two discrete side edges; each bridgingmember of the first multi-plate electrode connects a side edge of oneplate of a discrete pair of successive plates of the first multi-plateelectrode with a side edge of the other plate of that pair of platesadjacent the top edges of those plates; and each bridging member of thesecond multi-plate electrode connects a side edge of one plate of adiscrete pair of successive plates of the second multi-plate electrodewith a side edge of the other plate of that pair of plates adjacent thebottom edges of those plates.